Harmony ONE Exploit: Attacker Allegedly Mints 4B Tokens

That alleged mint equals about 26% of ONE’s supply. Soon after, the token crashed toward a record low near $0.0005735, according to BeInCrypto.

What Happened in the Harmony ONE Exploit

The alert came from analyst Juiceberg at 01:42 UTC. In a post on X, he said on-chain data showed an unauthorized 4 billion ONE mint.

Harmony ran on roughly 15 billion ONE before the event. So the reported mint of 4 billion tokens works out to about 26% of that supply.

According to the analyst, the attacker then moved about 2.8 billion of the new tokens to exchanges. As a result, fresh sell pressure hit the market almost immediately.

A follow-up post estimated the remaining on-chain attacker balance at roughly 115 million ONE. That figure is about 2.9% of the minted amount.

How the Empty Blocks Mint Reportedly Worked

Harmony is a sharded Layer-1 that uses Effective Proof-of-Stake. Normally, validators produce blocks, and block rewards plus staking logic control how new ONE is issued.

The analyst described the attack as happening through empty blocks. In short, that points to a bug or a compromised signing key that let blocks trigger large mints.

Juiceberg also claimed the public totalSupply endpoint did not reflect the new tokens. So account balances and explorer sums could diverge from the reported API figure.

Still, that detail stays unproven for now. An endpoint can lag true supply if it caches a value or reads a separate ledger, yet no side-by-side numbers confirm it.

ONE Price Crashes to a Record Low

The market reacted fast. CoinDesk reported a drop of about 26% for ONE.

Some trackers showed steeper falls of 30% or more during Asian morning hours. Meanwhile, the record low printed near $0.0005735.

Before the incident, ONE traded around $0.0012. Later, it recovered slightly toward the $0.00083 to $0.00087 range as buyers stepped in.

Trading volume also surged. Reports pointed to more than $36 million across 24-hour windows, though trackers often lag during fast moves.

Harmony Moves to Freeze Funds

Harmony confirmed an incident on its official account. At 04:26 UTC, the team quoted the alert and said it was coordinating a response.

In a statement on X, Harmony wrote that it is working with exchanges to stop and freeze the funds. The team also said it is preparing a patch plus rollback options.

Then, at 05:25 UTC, Harmony published four wallet addresses tied to the attacker. Each came in both bech32 and hex form, so exchanges can match deposits precisely.

With that list, centralized venues can block incoming transfers and freeze balances. Still, freezes only work once tokens reach a cooperating exchange. Funds that stay on-chain remain hard to touch.

So far, the team has not confirmed the exact 4 billion figure or the root cause. Instead, it acted on the reported incident while it investigates.

What Is Verified and What Is Not

The core lead looks solid. Harmony’s own response and consistent coverage from CoinDesk, BeInCrypto, and CertiK back the broad story.

Security firm CertiK also flagged the event, noting that billions of ONE were falsely minted. Even so, that alert echoes the analyst’s numbers rather than a full post-mortem.

Yet the hard on-chain details remain unverified. According to the sources reviewed, no one has published the mint transaction hashes, the specific block numbers, or the exchange-deposit hashes.

The 4 billion number also traces mainly to one analyst. Because Harmony has not independently quantified it, readers should treat the figure as reported rather than confirmed.

Independent explorers such as explorer.harmony.one are the expected place to verify the mint. For now, no public aggregation of those transactions has surfaced.

A Third Strike for Harmony

This event lands on a chain with a difficult security record. In June 2022, the Horizon Bridge exploit drained about $100 million, later tied to the Lazarus Group.

Then, in December 2023, a staking bug improperly minted around 146.3 million ONE. By comparison, the current alleged mint is far larger in percentage terms.

As a result, community sentiment turned sharply bearish. Many holders framed the news as a repeat of past failures, while some called for buybacks or a burn after any recovery.

What Comes Next for Harmony ONE

Attention now turns to three questions. First, how much can exchanges actually freeze? Second, will Harmony execute a rollback? Third, what caused the mint?

A patch and a possible rollback could reshape the token’s supply and its story. Until Harmony shares transaction-level proof, though, key claims stay in the reported column.

OCT will track the Harmony ONE exploit as explorer data and any formal post-mortem arrive. This article is not financial advice, and fast-moving incidents like this can change quickly.